Gas chromatographic “in column” spectroscopic analysis

• US 9,599,567 B2
• Filed: 03/13/2014
• Issued: 03/21/2017
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: The Government Of The United States As Represented By The Secretary Of The Navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: McGill, R. Andrew, Furstenberg, Robert, Nguyen, Viet K., Kendziora, Chris, Papantonakis, Michael, Stievater, Todd H.
• Primary Examiner(s): Macchiarolo, Peter
• Assistant Examiner(s): Young, Monica S
• Application Number:
  US14/208,088
• Publication Number:
  US 20140260535A1
• Time in Patent Office: 1,104 Days
• Field of Search: 73/233.7
• US Class Current: 1/1
• CPC Class Codes: B01J 20/285 based on polymers
• CPC Class Codes: G01N 2021/4761 Mirror arrangements, e.g. in IR range
• CPC Class Codes: G01N 2030/025 Gas chromatography
• CPC Class Codes: G01N 21/0332 with temperature control control of temperature G05D23/00; cryostats F17C3/08
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/39 using tunable lasers
• CPC Class Codes: G01N 21/552 Attenuated total reflection
• CPC Class Codes: G01N 21/658 enhancement Raman, e.g. surface plasmons
• CPC Class Codes: G01N 21/7746 the waveguide coupled to a cavity resonator
• CPC Class Codes: G01N 30/02 Column chromatography
• CPC Class Codes: G01N 30/6034 joining multiple columns
• CPC Class Codes: G01N 30/6082 transparent to radiation
• CPC Class Codes: G01N 30/74 Optical detectors measurement of intensity, velocity, spectral content, polarisation, or phase of infrared, visible or ultraviolet light G01J

Abstract

A chemical detector for rapid, simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives having one or more gas chromatography columns each with a chemosorbent or a chemo-reactive stationary phase and an infrared-transparent base, a bright infrared light source, a mechanism to direct the light source to any point along any of the columns, and an infrared sensor. Another disclosed detector has one or more gas chromatography columns each on the surface of a substrate having at least one infrared-transparent waveguide pattern, a bright infrared light source, and at least one ring resonator for each column, where each ring resonator is coated with a chemosorbent or a chemo-reactive stationary phase, and where each ring resonator spectroscopically probes the stationary phase. Also disclosed are the related methods for chemical detection.

Claims

1. A chemical detector for simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives, comprising:

one or more gas chromatography columns, wherein each column comprises one or more chemosorbent or chemo-reactive stationary phases, and wherein each column comprises an infrared evanescent waveguide configured to detect along the length of the column;

an infrared light source;

a moveable mirror to direct the light source to the more than one gas chromatography columns, wherein the light source can be directed to any point along any of the columns or to a preconcentrator or collector device, wherein in-column chemical detection can occur at all points along every column; and

an infrared sensor.

2. The chemical detector of claim 1, wherein when there is more than one column, each column is operated in parallel.

3. The chemical detector of claim 1, wherein at least one stationary phase comprises a carbosilane material with hydrogen bond acidic functionalization.

4. The chemical detector of claim 1, wherein the infrared evanescent waveguide comprises an attenuated total reflection (ATR) crystal.

5. The chemical detector of claim 1, wherein the infrared light source comprises one or more optionally tunable infrared lasers, and more preferably the bright infrared light source comprises one or more quantum cascade lasers (QCLs).

6. The chemical detector of claim 1, additionally comprising an analyte preconcentrator comprising sorbent coated structures positioned before or at the inlet end of at least one of the columns.

7. The chemical detector of claim 1, additionally comprising one or more independently controlled heating elements along one or more columns.

8. A method for simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives, comprising:

injecting a vapor-phase analyte sample into one or more gas chromatography columns, wherein each column comprises one or more chemosorbent or chemo-reactive stationary phases, and wherein each column comprises an infrared evanescent waveguide configured to detect along the length of the column;

directing an infrared light source to a point at one of the columns, wherein the light source can be directed to any point along any of the columns or to a preconcentrator or collector device, wherein in-column chemical detection can occur at all points along every column; and

using an infrared sensor to detect for the presence of chemicals.

9. The method of claim 8, wherein when there is more than one column, each column is operated in parallel.

10. The method of claim 8, wherein at least one stationary phase comprises a carbosilane material with hydrogen bond acidic functionalization.

11. The method of claim 8, wherein the infrared evanescent waveguide comprises an attenuated total reflection (ATR) crystal.

12. The method of claim 8, wherein the infrared light source comprises one or more optionally tunable infrared lasers, and more preferably the bright infrared light source comprises one or more quantum cascade lasers (QCL).

13. A chemical detector for simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives, comprising:

one or more gas chromatography columns, wherein each column is on a surface of a substrate, wherein the substrate has one or more waveguides patterned on the surface to guide light to detect one or more chemical species at a specific location at one of the gas chromatography columns, and wherein each waveguide pattern is transparent to infrared light;

an infrared light source; and

at least one ring resonator for each column, wherein each ring resonator is coated with one or more chemosorbent or chemo-reactive stationary phases, and wherein each ring resonator spectroscopically probes the stationary phase.

14. The chemical detector of claim 13, wherein when there is more than one column, each column is operated in parallel.

15. The chemical detector of claim 13, wherein at least one stationary phase comprises a carbosilane material with hydrogen bond acidic functionalization.

16. The chemical detector of claim 13, wherein the infrared light comprises one or more optionally tunable infrared lasers, and more preferably the bright infrared light source comprises one or more quantum cascade lasers (QCL).

17. The chemical detector of claim 13, additionally comprising a preconcentrator before or at the head of at least one of the columns.

18. The chemical detector of claim 13, additionally comprising one or more independently controlled heating elements along one or more columns.

19. The chemical detector of claim 13, wherein the detector is a hand held device.

20. A method for simultaneous detection of multiple chemicals including chemical warfare agents, toxic industrial chemicals, and explosives, comprising:

injecting a vapor-phase analyte sample into one or more gas chromatography columns, wherein each column is on a surface of a substrate, wherein the substrate has one or more waveguides patterned on the surface to guide light to detect one or more chemical species at a specific location at one of the gas chromatography columns, and wherein each waveguide pattern is transparent to infrared light;

directing an infrared light into each waveguide; and

using a ring resonator to spectroscopically probe the stationary phase of a column, wherein there is at least one ring resonator for each column, and wherein each ring resonator is coated with one or more chemosorbent or chemo-reactive stationary phases.

21. The method of claim 20, wherein when there is more than one column, each column is operated in parallel.

22. The method of claim 20, wherein at least one stationary phase comprises a carbosilane material with hydrogen bond acidic functionalization.

23. The method of claim 20, wherein the infrared light source comprises one or more optionally tunable infrared lasers, and more preferably the bright infrared light source comprises one or more quantum cascade lasers (QCL).